1 /*****************************************************************************
2 * mpeg_system.c: TS, PS and PES management
3 *****************************************************************************
4 * Copyright (C) 1998, 1999, 2000 VideoLAN
5 * $Id: mpeg_system.c,v 1.35 2001/02/12 07:52:40 sam Exp $
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
8 * Michel Lespinasse <walken@via.ecp.fr>
9 * BenoƮt Steiner <benny@via.ecp.fr>
10 * Samuel Hocevar <sam@via.ecp.fr>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
41 #include "stream_control.h"
42 #include "input_ext-intf.h"
43 #include "input_ext-dec.h"
46 #include "mpeg_system.h"
48 #include "main.h" /* AC3/MPEG channel, SPU channel */
50 /*****************************************************************************
52 *****************************************************************************/
56 * PES Packet management
59 /*****************************************************************************
61 *****************************************************************************
62 * Small utility function used to parse discontinuous headers safely. Copies
63 * i_buf_len bytes of data to a buffer and returns the size copied.
64 * This is a variation on the theme of input_ext-dec.h:GetChunk().
65 *****************************************************************************/
66 static __inline__ size_t MoveChunk( byte_t * p_dest,
67 data_packet_t ** pp_data_src,
71 ptrdiff_t i_available;
73 if( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
77 memcpy( p_dest, *pp_src, i_buf_len );
83 size_t i_init_len = i_buf_len;
88 memcpy( p_dest, *pp_src, i_available );
89 *pp_data_src = (*pp_data_src)->p_next;
90 i_buf_len -= i_available;
91 p_dest += i_available;
92 if( *pp_data_src == NULL )
95 return( i_init_len - i_buf_len );
97 *pp_src = (*pp_data_src)->p_payload_start;
99 while( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
105 memcpy( p_dest, *pp_src, i_buf_len );
106 *pp_src += i_buf_len;
108 return( i_init_len );
112 /*****************************************************************************
114 *****************************************************************************
115 * Parse a finished PES packet and analyze its header.
116 *****************************************************************************/
117 #define PES_HEADER_SIZE 7
118 void input_ParsePES( input_thread_t * p_input, es_descriptor_t * p_es )
120 data_packet_t * p_data;
122 byte_t p_header[PES_HEADER_SIZE];
125 #define p_pes (p_es->p_pes)
127 //intf_DbgMsg("End of PES packet %p", p_pes);
129 /* Parse the header. The header has a variable length, but in order
130 * to improve the algorithm, we will read the 14 bytes we may be
132 p_data = p_pes->p_first;
133 p_byte = p_data->p_payload_start;
136 if( MoveChunk( p_header, &p_data, &p_byte, PES_HEADER_SIZE )
139 intf_WarnMsg( 3, "PES packet too short to have a header" );
140 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
145 /* Get the PES size if defined */
146 p_es->i_pes_real_size = U16_AT(p_header + 4) + 6;
148 /* First read the 6 header bytes common to all PES packets:
149 * use them to test the PES validity */
150 if( (p_header[0] || p_header[1] || (p_header[2] != 1)) )
152 /* packet_start_code_prefix != 0x000001 */
153 intf_ErrMsg( "PES packet doesn't start with 0x000001 : data loss" );
154 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
159 int i_pes_header_size, i_payload_size;
161 if ( p_es->i_pes_real_size &&
162 (p_es->i_pes_real_size != p_pes->i_pes_size) )
164 /* PES_packet_length is set and != total received payload */
165 /* Warn the decoder that the data may be corrupt. */
166 intf_WarnMsg( 3, "PES sizes do not match : packet corrupted" );
169 switch( p_es->i_stream_id )
171 case 0xBC: /* Program stream map */
172 case 0xBE: /* Padding */
173 case 0xBF: /* Private stream 2 */
176 case 0xFF: /* Program stream directory */
177 case 0xF2: /* DSMCC stream */
178 case 0xF8: /* ITU-T H.222.1 type E stream */
179 /* The payload begins immediately after the 6 bytes header, so
180 * we have finished with the parsing */
181 i_pes_header_size = 6;
185 if( (p_header[6] & 0xC0) == 0x80 )
187 /* MPEG-2 : the PES header contains at least 3 more bytes. */
189 boolean_t b_has_pts, b_has_dts;
190 byte_t p_full_header[12];
192 p_pes->b_data_alignment = p_header[6] & 0x04;
194 i_max_len = MoveChunk( p_full_header, &p_data, &p_byte, 12 );
198 "PES packet too short to have a MPEG-2 header" );
199 p_input->pf_delete_pes( p_input->p_method_data,
205 b_has_pts = p_full_header[0] & 0x80;
206 b_has_dts = p_full_header[0] & 0x40;
207 i_pes_header_size = p_full_header[1] + 9;
209 /* Now parse the optional header extensions */
215 "PES packet too short to have a MPEG-2 header" );
216 p_input->pf_delete_pes( p_input->p_method_data,
221 p_pes->i_pts = input_ClockGetTS( p_input, p_es->p_pgrm,
222 ( ((mtime_t)(p_full_header[2] & 0x0E) << 29) |
223 (((mtime_t)U16_AT(p_full_header + 3) << 14) - (1 << 14)) |
224 ((mtime_t)U16_AT(p_full_header + 5) >> 1) ) );
231 "PES packet too short to have a MPEG-2 header" );
232 p_input->pf_delete_pes( p_input->p_method_data,
237 p_pes->i_dts = input_ClockGetTS( p_input, p_es->p_pgrm,
238 ( ((mtime_t)(p_full_header[7] & 0x0E) << 29) |
239 (((mtime_t)U16_AT(p_full_header + 8) << 14)
241 ((mtime_t)U16_AT(p_full_header + 10) >> 1) ) );
247 /* Probably MPEG-1 */
248 boolean_t b_has_pts, b_has_dts;
250 i_pes_header_size = 6;
251 p_data = p_pes->p_first;
252 p_byte = p_data->p_payload_start;
253 /* Cannot fail because the previous one succeeded. */
254 MoveChunk( NULL, &p_data, &p_byte, 6 );
256 while( *p_byte == 0xFF && i_pes_header_size < 22 )
259 if( MoveChunk( NULL, &p_data, &p_byte, 1 ) != 1 )
262 "PES packet too short to have a MPEG-1 header" );
263 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
268 if( i_pes_header_size == 22 )
270 intf_ErrMsg( "Too much MPEG-1 stuffing" );
271 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
276 if( (*p_byte & 0xC0) == 0x40 )
278 /* Don't ask why... --Meuuh */
279 /* Erm... why ? --Sam */
280 /* Well... According to the recommendation, it is for
281 * STD_buffer_scale and STD_buffer_size. --Meuuh */
282 i_pes_header_size += 2;
283 if( MoveChunk( NULL, &p_data, &p_byte, 2 ) != 2 )
286 "PES packet too short to have a MPEG-1 header" );
287 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
295 b_has_pts = *p_byte & 0x20;
296 b_has_dts = *p_byte & 0x10;
302 i_pes_header_size += 4;
303 if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
306 "PES packet too short to have a MPEG-1 header" );
307 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
312 p_pes->i_pts = input_ClockGetTS( p_input, p_es->p_pgrm,
313 ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
314 (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
315 ((mtime_t)U16_AT(p_ts + 3) >> 1) ) );
319 i_pes_header_size += 5;
320 if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
323 "PES packet too short to have a MPEG-1 header" );
324 p_input->pf_delete_pes( p_input->p_method_data,
330 p_pes->i_dts = input_ClockGetTS( p_input,
332 ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
333 (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
334 ((mtime_t)U16_AT(p_ts + 3) >> 1) ) );
342 if( p_es->i_stream_id == 0xbd )
344 /* With private stream 1, the first byte of the payload
345 * is a stream_private_id, so skip it. */
349 /* Now we've parsed the header, we just have to indicate in some
350 * specific data packets where the PES payload begins (renumber
351 * p_payload_start), so that the decoders can find the beginning
352 * of their data right out of the box. */
353 p_data = p_pes->p_first;
354 i_payload_size = p_data->p_payload_end
355 - p_data->p_payload_start;
356 while( i_pes_header_size > i_payload_size )
358 /* These packets are entirely filled by the PES header. */
359 i_pes_header_size -= i_payload_size;
360 p_data->p_payload_start = p_data->p_payload_end;
361 /* Go to the next data packet. */
362 if( (p_data = p_data->p_next) == NULL )
364 intf_ErrMsg( "PES header bigger than payload" );
365 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
369 i_payload_size = p_data->p_payload_end
370 - p_data->p_payload_start;
372 /* This last packet is partly header, partly payload. */
373 if( i_payload_size < i_pes_header_size )
375 intf_ErrMsg( "PES header bigger than payload" );
376 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
380 p_data->p_payload_start += i_pes_header_size;
382 /* Now we can eventually put the PES packet in the decoder's
384 if( p_es->p_decoder_fifo != NULL )
386 input_DecodePES( p_es->p_decoder_fifo, p_pes );
390 intf_ErrMsg("No fifo to receive PES %p (who wrote this damn code ?)",
392 p_input->pf_delete_pes( p_input->p_method_data, p_pes );
400 /*****************************************************************************
402 *****************************************************************************
403 * Gather a PES packet.
404 *****************************************************************************/
405 void input_GatherPES( input_thread_t * p_input, data_packet_t * p_data,
406 es_descriptor_t * p_es,
407 boolean_t b_unit_start, boolean_t b_packet_lost )
409 #define p_pes (p_es->p_pes)
411 //intf_DbgMsg("PES-demultiplexing %p (%p)", p_ts_packet, p_pes);
413 /* If we lost data, insert a NULL data packet (philosophy : 0 is quite
414 * often an escape sequence in decoders, so that should make them wait
415 * for the next start code). */
418 input_NullPacket( p_input, p_es );
421 if( b_unit_start && p_pes != NULL )
423 /* If the data packet contains the begining of a new PES packet, and
424 * if we were reassembling a PES packet, then the PES should be
425 * complete now, so parse its header and give it to the decoders. */
426 input_ParsePES( p_input, p_es );
429 if( !b_unit_start && p_pes == NULL )
431 /* Random access... */
432 p_input->pf_delete_packet( p_input->p_method_data, p_data );
438 /* If we are at the beginning of a new PES packet, we must fetch
439 * a new PES buffer to begin with the reassembly of this PES
440 * packet. This is also here that we can synchronize with the
441 * stream if we lost packets or if the decoder has just
443 if( (p_pes = p_input->pf_new_pes( p_input->p_method_data ) ) == NULL )
445 intf_ErrMsg("Out of memory");
446 p_input->b_error = 1;
449 p_pes->i_rate = p_input->stream.control.i_rate;
450 p_pes->p_first = p_data;
452 /* If the PES header fits in the first data packet, we can
453 * already set p_gather->i_pes_real_size. */
454 if( p_data->p_payload_end - p_data->p_payload_start
457 p_es->i_pes_real_size =
458 U16_AT(p_data->p_payload_start + 4) + 6;
462 p_es->i_pes_real_size = 0;
467 /* Update the relations between the data packets */
468 p_es->p_last->p_next = p_data;
471 p_es->p_last = p_data;
473 /* Size of the payload carried in the data packet */
474 p_pes->i_pes_size += (p_data->p_payload_end
475 - p_data->p_payload_start);
477 /* We can check if the packet is finished */
478 if( p_pes->i_pes_size == p_es->i_pes_real_size )
480 /* The packet is finished, parse it */
481 input_ParsePES( p_input, p_es );
492 /*****************************************************************************
493 * GetID: Get the ID of a stream
494 *****************************************************************************/
495 static u16 GetID( data_packet_t * p_data )
499 i_id = p_data->p_buffer[3]; /* stream_id */
502 /* stream_private_id */
503 i_id |= p_data->p_buffer[ 9 + p_data->p_buffer[8] ] << 8;
508 /*****************************************************************************
509 * DecodePSM: Decode the Program Stream Map information
510 *****************************************************************************/
511 static void DecodePSM( input_thread_t * p_input, data_packet_t * p_data )
513 stream_ps_data_t * p_demux =
514 (stream_ps_data_t *)p_input->stream.p_demux_data;
518 int i_new_es_number = 0;
520 intf_Msg("input info: Your stream contains Program Stream Map information");
521 intf_Msg("input info: Please send a mail to <massiot@via.ecp.fr>");
523 if( p_data->p_payload_start + 10 > p_data->p_payload_end )
525 intf_ErrMsg( "PSM too short : packet corrupt" );
529 if( p_demux->b_has_PSM
530 && p_demux->i_PSM_version == (p_data->p_buffer[6] & 0x1F) )
532 /* Already got that one. */
536 intf_DbgMsg( "Building PSM" );
537 p_demux->b_has_PSM = 1;
538 p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
540 /* Go to elementary_stream_map_length, jumping over
541 * program_stream_info. */
542 p_byte = p_data->p_payload_start + 10
543 + U16_AT(&p_data->p_payload_start[8]);
544 if( p_byte > p_data->p_payload_end )
546 intf_ErrMsg( "PSM too short : packet corrupt" );
549 /* This is the full size of the elementary_stream_map.
550 * 2 == elementary_stream_map_length
551 * Please note that CRC_32 is not included in the length. */
552 p_end = p_byte + 2 + U16_AT(p_byte);
554 if( p_end > p_data->p_payload_end )
556 intf_ErrMsg( "PSM too short : packet corrupt" );
560 vlc_mutex_lock( &p_input->stream.stream_lock );
562 /* 4 == minimum useful size of a section */
563 while( p_byte + 4 <= p_end )
565 es_descriptor_t * p_es = NULL;
566 u8 i_stream_id = p_byte[1];
567 /* FIXME: there will be a problem with private streams... (same
570 /* Look for the ES in the ES table */
571 for( i = i_new_es_number;
572 i < p_input->stream.pp_programs[0]->i_es_number;
575 if( p_input->stream.pp_programs[0]->pp_es[i]->i_stream_id
578 p_es = p_input->stream.pp_programs[0]->pp_es[i];
579 if( p_es->i_type != p_byte[0] )
581 input_DelES( p_input, p_es );
586 /* Move the ES to the beginning. */
587 p_input->stream.pp_programs[0]->pp_es[i]
588 = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
589 p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ]
597 /* The goal is to have all the ES we have just read in the
598 * beginning of the pp_es table, and all the others at the end,
599 * so that we can close them more easily at the end. */
602 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
604 p_es->i_type = p_byte[0];
605 p_es->b_audio = ( p_es->i_type == MPEG1_AUDIO_ES
606 || p_es->i_type == MPEG2_AUDIO_ES
607 || p_es->i_type == AC3_AUDIO_ES
608 || p_es->i_type == LPCM_AUDIO_ES
611 /* input_AddES has inserted the new element at the end. */
612 p_input->stream.pp_programs[0]->pp_es[
613 p_input->stream.pp_programs[0]->i_es_number ]
614 = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
615 p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ] = p_es;
618 p_byte += 4 + U16_AT(&p_byte[2]);
621 /* Un-select the streams that are no longer parts of the program. */
622 for( i = i_new_es_number;
623 i < p_input->stream.pp_programs[0]->i_es_number;
626 /* We remove pp_es[i_new_es_member] and not pp_es[i] because the
627 * list will be emptied starting from the end */
628 input_DelES( p_input,
629 p_input->stream.pp_programs[0]->pp_es[i_new_es_number] );
633 intf_Msg( "input info: The stream map after the PSM is now :" );
634 input_DumpStream( p_input );
637 vlc_mutex_unlock( &p_input->stream.stream_lock );
640 /*****************************************************************************
641 * input_ParsePS: read the PS header
642 *****************************************************************************/
643 es_descriptor_t * input_ParsePS( input_thread_t * p_input,
644 data_packet_t * p_data )
647 es_descriptor_t * p_es = NULL;
649 i_code = U32_AT( p_data->p_buffer );
650 if( i_code > 0x1BC ) /* ES start code */
655 /* This is a PES packet. Find out if we want it or not. */
656 i_id = GetID( p_data );
658 vlc_mutex_lock( &p_input->stream.stream_lock );
659 if( p_input->stream.pp_programs[0]->b_is_ok )
661 /* Look only at the selected ES. */
662 for( i_dummy = 0; i_dummy < p_input->stream.i_selected_es_number;
665 if( p_input->stream.pp_selected_es[i_dummy] != NULL
666 && p_input->stream.pp_selected_es[i_dummy]->i_id == i_id )
668 p_es = p_input->stream.pp_selected_es[i_dummy];
675 stream_ps_data_t * p_demux =
676 (stream_ps_data_t *)p_input->stream.pp_programs[0]->p_demux_data;
678 /* Search all ES ; if not found -> AddES */
679 p_es = input_FindES( p_input, i_id );
681 if( p_es == NULL && !p_demux->b_has_PSM )
683 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
687 p_es->i_stream_id = p_data->p_buffer[3];
689 /* Set stream type and auto-spawn. */
690 if( (i_id & 0xF0) == 0xE0 )
693 p_es->i_type = MPEG2_VIDEO_ES;
695 if( !p_input->stream.b_seekable )
696 input_SelectES( p_input, p_es );
699 else if( (i_id & 0xE0) == 0xC0 )
702 p_es->i_type = MPEG2_AUDIO_ES;
705 if( !p_input->stream.b_seekable )
706 if( main_GetIntVariable( INPUT_CHANNEL_VAR, 0 )
707 == (p_es->i_id & 0x1F) )
708 switch( main_GetIntVariable( INPUT_AUDIO_VAR, 0 ) )
711 main_PutIntVariable( INPUT_CHANNEL_VAR,
714 input_SelectES( p_input, p_es );
718 else if( (i_id & 0xF0FF) == 0x80BD )
720 /* AC3 audio (0x80->0x8F) */
721 p_es->i_type = AC3_AUDIO_ES;
724 if( !p_input->stream.b_seekable )
725 if( main_GetIntVariable( INPUT_CHANNEL_VAR, 0 )
726 == ((p_es->i_id & 0xF00) >> 8) )
727 switch( main_GetIntVariable( INPUT_AUDIO_VAR, 0 ) )
730 main_PutIntVariable( INPUT_CHANNEL_VAR,
733 input_SelectES( p_input, p_es );
737 else if( (i_id & 0xE0FF) == 0x20BD )
739 /* Subtitles video (0x20->0x3F) */
740 p_es->i_type = DVD_SPU_ES;
742 if( main_GetIntVariable( INPUT_SUBTITLE_VAR, -1 )
743 == ((p_es->i_id & 0x1F00) >> 8) )
745 if( !p_input->stream.b_seekable )
746 input_SelectES( p_input, p_es );
750 else if( (i_id & 0xF0FF) == 0xA0BD )
752 /* LPCM audio (0xA0->0xAF) */
753 p_es->i_type = LPCM_AUDIO_ES;
755 /* FIXME : write the decoder */
759 p_es->i_type = UNKNOWN_ES;
763 } /* stream.b_is_ok */
764 vlc_mutex_unlock( &p_input->stream.stream_lock );
765 } /* i_code > 0xBC */
770 /*****************************************************************************
771 * input_DemuxPS: first step of demultiplexing: the PS header
772 *****************************************************************************/
773 void input_DemuxPS( input_thread_t * p_input, data_packet_t * p_data )
776 boolean_t b_trash = 0;
777 es_descriptor_t * p_es = NULL;
779 i_code = U32_AT( p_data->p_buffer );
780 if( i_code <= 0x1BC )
784 case 0x1BA: /* PACK_START_CODE */
789 if( (p_data->p_buffer[4] & 0xC0) == 0x40 )
793 ((mtime_t)(p_data->p_buffer[4] & 0x38) << 27) |
794 ((mtime_t)(U32_AT(p_data->p_buffer + 4) & 0x03FFF800)
796 ((mtime_t)(U32_AT(p_data->p_buffer + 6) & 0x03FFF800)
801 /* MPEG-1 SCR is like PTS. */
803 ((mtime_t)(p_data->p_buffer[4] & 0x0E) << 29) |
804 (((mtime_t)U16_AT(p_data->p_buffer + 5) << 14)
806 ((mtime_t)U16_AT(p_data->p_buffer + 7) >> 1);
808 /* Call the pace control. */
809 //intf_Msg("+%lld", scr_time);
810 input_ClockManageRef( p_input, p_input->stream.pp_programs[0],
816 case 0x1BB: /* SYSTEM_START_CODE */
817 b_trash = 1; /* Nothing interesting */
820 case 0x1BC: /* PROGRAM_STREAM_MAP_CODE */
821 DecodePSM( p_input, p_data );
825 case 0x1B9: /* PROGRAM_END_CODE */
830 /* This should not happen */
832 intf_WarnMsg( 1, "Unwanted packet received with start code %x",
838 p_es = input_ParsePS( p_input, p_data );
840 vlc_mutex_lock( &p_input->stream.control.control_lock );
841 if( p_es != NULL && p_es->p_decoder_fifo != NULL
842 && (!p_es->b_audio || !p_input->stream.control.b_mute) )
844 vlc_mutex_unlock( &p_input->stream.control.control_lock );
848 input_GatherPES( p_input, p_data, p_es, 1, 0 );
852 vlc_mutex_unlock( &p_input->stream.control.control_lock );
857 /* Trash the packet if it has no payload or if it isn't selected */
860 p_input->pf_delete_packet( p_input->p_method_data, p_data );
862 p_input->c_packets_trashed++;
872 /*****************************************************************************
873 * input_DemuxTS: first step of demultiplexing: the TS header
874 *****************************************************************************/
875 void input_DemuxTS( input_thread_t * p_input, data_packet_t * p_data )
878 boolean_t b_adaptation; /* Adaptation field is present */
879 boolean_t b_payload; /* Packet carries payload */
880 boolean_t b_unit_start; /* A PSI or a PES start in the packet */
881 boolean_t b_trash = 0; /* Is the packet unuseful ? */
882 boolean_t b_lost = 0; /* Was there a packet loss ? */
883 es_descriptor_t * p_es = NULL;
884 es_ts_data_t * p_es_demux = NULL;
885 pgrm_ts_data_t * p_pgrm_demux = NULL;
887 #define p (p_data->p_buffer)
889 //intf_DbgMsg("input debug: TS-demultiplexing packet %p, pid %d",
890 // p_ts_packet, U16_AT(&p[1]) & 0x1fff);
892 /* Extract flags values from TS common header. */
893 i_pid = U16_AT(&p[1]) & 0x1fff;
894 b_unit_start = (p[1] & 0x40);
895 b_adaptation = (p[3] & 0x20);
896 b_payload = (p[3] & 0x10);
898 /* Find out the elementary stream. */
899 vlc_mutex_lock( &p_input->stream.stream_lock );
900 p_es = input_FindES( p_input, i_pid );
902 vlc_mutex_lock( &p_input->stream.control.control_lock );
903 if( p_es == NULL || p_es->p_decoder_fifo == NULL
904 || (p_es->b_audio && p_input->stream.control.b_mute) )
906 /* Not selected. Just read the adaptation field for a PCR. */
909 vlc_mutex_unlock( &p_input->stream.control.control_lock );
910 vlc_mutex_unlock( &p_input->stream.stream_lock );
912 if( (p_es->p_decoder_fifo != NULL) || (p_pgrm_demux->i_pcr_pid == i_pid) )
918 /* Extract adaptation field information if any */
921 /* We don't have any adaptation_field, so payload starts
922 * immediately after the 4 byte TS header */
923 p_data->p_payload_start += 4;
927 /* p[4] is adaptation_field_length minus one */
928 p_data->p_payload_start += 5 + p[4];
930 /* The adaptation field can be limited to the
931 * adaptation_field_length byte, so that there is nothing to do:
932 * skip this possibility */
935 /* If the packet has both adaptation_field and payload,
936 * adaptation_field cannot be more than 182 bytes long; if
937 * there is only an adaptation_field, it must fill the next
939 if( b_payload ? (p[4] > 182) : (p[4] != 183) )
942 "invalid TS adaptation field (%p)",
944 p_data->b_discard_payload = 1;
946 p_es->c_invalid_packets++;
950 /* Now we are sure that the byte containing flags is present:
954 /* discontinuity_indicator */
958 "discontinuity_indicator"
959 " encountered by TS demux (position read: %d,"
961 p[5] & 0x80, p_es_demux->i_continuity_counter );
963 /* If the PID carries the PCR, there will be a system
964 * time-based discontinuity. We let the PCR decoder
966 p_es->p_pgrm->i_synchro_state = SYNCHRO_REINIT;
968 /* There also may be a continuity_counter
969 * discontinuity: resynchronise our counter with
970 * the one of the stream. */
971 p_es_demux->i_continuity_counter = (p[3] & 0x0f) - 1;
974 /* If this is a PCR_PID, and this TS packet contains a
975 * PCR, we pass it along to the PCR decoder. */
976 if( (p_pgrm_demux->i_pcr_pid == i_pid) && (p[5] & 0x10) )
978 /* There should be a PCR field in the packet, check
979 * if the adaptation field is long enough to carry
986 ( (mtime_t)U32_AT((u32*)&p[6]) << 1 )
988 /* Call the pace control. */
989 input_ClockManageRef( p_input, p_es->p_pgrm,
993 } /* valid TS adaptation field ? */
995 } /* has adaptation field */
997 /* Check the continuity of the stream. */
998 i_dummy = ((p[3] & 0x0f) - p_es_demux->i_continuity_counter) & 0x0f;
1001 /* Everything is ok, just increase our counter */
1002 p_es_demux->i_continuity_counter++;
1006 if( !b_payload && i_dummy == 0 )
1008 /* This is a packet without payload, this is allowed by the
1009 * draft. As there is nothing interesting in this packet
1010 * (except PCR that have already been handled), we can trash
1013 "Packet without payload received by TS demux" );
1016 else if( i_dummy <= 0 )
1018 /* FIXME: this can never happen, can it ? --Meuuh */
1019 /* Duplicate packet: mark it as being to be trashed. */
1020 intf_WarnMsg( 1, "Duplicate packet received by TS demux" );
1023 else if( p_es_demux->i_continuity_counter == 0xFF )
1025 /* This means that the packet is the first one we receive for
1026 * this ES since the continuity counter ranges between 0 and
1027 * 0x0F excepts when it has been initialized by the input:
1028 * init the counter to the correct value. */
1029 intf_DbgMsg( "First packet for PID %d received by TS demux",
1031 p_es_demux->i_continuity_counter = (p[3] & 0x0f);
1035 /* This can indicate that we missed a packet or that the
1036 * continuity_counter wrapped and we received a dup packet:
1037 * as we don't know, do as if we missed a packet to be sure
1038 * to recover from this situation */
1040 "Packet lost by TS demux: current %d, packet %d",
1041 p_es_demux->i_continuity_counter & 0x0f,
1044 p_es_demux->i_continuity_counter = p[3] & 0x0f;
1045 } /* not continuous */
1047 } /* if selected or PCR */
1049 /* Trash the packet if it has no payload or if it isn't selected */
1052 p_input->pf_delete_packet( p_input, p_data );
1054 p_input->c_packets_trashed++;
1059 if( p_es_demux->b_psi )
1061 /* The payload contains PSI tables */
1063 /* FIXME ! write the PSI decoder :p */
1064 input_DemuxPSI( p_input, p_data, p_es,
1065 b_unit_start, b_lost );
1070 /* The payload carries a PES stream */
1072 input_GatherPES( p_input, p_data, p_es, b_unit_start, b_lost );